Summary of Dimensions and Facts :-

1.)What is Dimension Table ?

Dimensions are Tables ,Attributes are columns in Dimension Tables. Attributes Describe the characteristics of data such as product size and product color . Through attributes you can group and analyze members of dimension based on characteristics. Dimension tables are referenced by fact table using keys. When creating a dimension table in a data ware house, a system-generated key is used to uniquely identify a row in the dimension . The surrogate key is used as the primary key in the dimension table . The surrogate key is placed in the fact table and a foreign key is defined between the two tables .when the data is joined ,it does so just as any other join within the database.

2.)What is Fact Table ?

Measures are columns in Fact Tables.

Fact tables have foreign key columns  referring to the Dimension Tables along with Measure Columns.Measure column values can be used to perform some sort of mathematical function.
In general dimension tables holds the description /textual information about facts stored in fact tables.

Dimension tables are referenced by fact table using keys.

Example:-
Measure is a revenue of a company. you find average revenue and overall revenue
What if one wants to know Revenue per Day or Revenue per Product or Revenue per Country?
These are Dimensions : Date,Product ,Country .Dimensions give you context for measure.
 An attribute is similar to dimension and sometimes is used interchangeably. However ,one
Dimension can have multiple attributes :what day of the year is a date ?What week of the year is a date ?